Oral Gonadotropin-Releasing Hormone Antagonists for the Treatment of Uterine Leiomyomas

Uterine leiomyomas are common hormone-responsive neoplasms that frequently cause heavy menstrual bleeding, anemia, pelvic pressure, pain, and adverse reproductive outcomes. In this overview, the efficacy and safety of oral gonadotropin-releasing hormone (GnRH) antagonists, co-administered with menopausal replacement-level steroid hormones or used at doses to avoid complete hypothalamic suppression, are reviewed for the management of uterine leiomyomas. Oral GnRH antagonists provide rapid suppression of sex steroids and avoid the initial steroidal flare and resultant temporary worsening of symptoms typically seen with parenteral GnRH agonists. Oral GnRH antagonists are effective in reducing leiomyoma-associated heavy menstrual bleeding, with high rates of amenorrhea and improved anemia and leiomyoma-associated pain, and providing modest reduction in uterine volume when used in combination with menopausal replacement-level steroid hormones. This add-back therapy can reduce hypogonadal side effects, including hot flushes and bone mineral density loss, close to levels seen with placebo therapy. Currently, both elagolix 300 mg twice daily with once-daily estradiol (1 mg) and norethindrone (0.5 mg) and relugolix 40 mg once daily with estradiol (1 mg) and norethindrone (0.5 mg) combination therapy are approved for leiomyoma treatment by the U.S. Food and Drug Administration. Linzagolix is under investigation in the United States but approved at two does with and without steroid hormones in the European Union. The efficacy of these agents appears to be robust over a wide spectrum of clinical presentations, demonstrating that worse disease parameters at baseline do not appear to inhibit efficacy. Across clinical trials, participants largely reflected the population of individuals affected by uterine leiomyomas.